1. Field of the Invention
The present invention relates to a process for producing a bisthiophenolperfluoroalkylidene compound, and more particularly to a process for producing a bisthiophenol- perfluoroalkylidene compound effectively applicable as a precursor for synthesis of polysulfide or as a cross-linking agent for fluorine-containing polymers.
2. Related Prior Art
U.S. Pat. No.4,720,590 discloses that 2,2-bis(mercapto-phenyl)hexafluoropropane [2, 2, 2-trifluoro-l-(trifluoromethyl)-ethylidene-bisbenzenethiol] represented by the following formula: ##STR1## can be effectively used as a precursor for synthesis of polysulfide.
In such a compound, the SH group can take the m- or p-position. The m-substituted compound can be obtained from 2,2'-bisphenylhexafluoropropane as a starting material through total 7 synthesis steps, and the yield through the total 7 steps is not definitely disclosed therein because of incomplete disclosure of indivisual step yields, and seems not to exceed about 50%. Thus, it seems that the desired compound is not obtained in good yield.